Hspec unable to load interface for Spec file - haskell

Question

I am trying to run hspec but getting error as "Failed to load interface for Spec file". I tried similar example from github, got same error. Please suggest where I am going wrong...(PS: I am able to run this with stack).
Example from github (https://github.com/FranklinChen/twenty-four-days2015-of-hackage)
I have following files:
-- src.HintExample.hs
module HintExample where
import SortWrapper (Sort)
import qualified Language.Haskell.Interpreter as I
import Language.Haskell.Interpreter (OptionVal((:=)))
-- | Dynamically load a 'Sort' implementation from a file.
-- src is needed to pick up our SortWrapper.
-- sort-plugins is a sample user plugins directory
loadSort :: I.MonadInterpreter m =>
String -- ^ module name
-> String -- ^ function name
-> m Sort
loadSort moduleName functionName = do
I.set [I.searchPath := ["src", "sort-plugins"]]
I.loadModules [moduleName]
I.setImports [moduleName, "SortWrapper"]
I.interpret (moduleName ++ "." ++ functionName) (I.as :: Sort)
And test file as
-- test.HintExampleSpec.hs
module HintExampleSpec where
import SortWrapper (Sort(Sort))
import HintExample (loadSort)
import qualified Language.Haskell.Interpreter as I
import Test.Hspec (Spec, hspec, describe, it, shouldBe)
import Test.Hspec.QuickCheck (prop)
-- | Required for auto-discovery.
spec :: Spec
spec =
describe "hint" $ do
it "dynamically loads a correct polymorphic sort function" $ do
Right (Sort ourSort) <-
I.runInterpreter (loadSort "OurSorter" "ourSort")
ourSort "ebcad" `shouldBe` "abcde"
ourSort [1 :: Int, 5, 4, 3, 7] `shouldBe` [1, 3, 4, 5, 7]
it "dynamically loads a wrong (only head) sort function" $ do
Right (Sort onlyHead) <-
I.runInterpreter (loadSort "OurSorter" "onlyHead")
onlyHead "ebcad" `shouldBe` "e"
onlyHead [True, False] `shouldBe` [True]
main :: IO ()
main = hspec spec
Spec file (Spec.hs) in test directory as:
{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
running as:
runhaskell test/Spec.hs